Apparatus for perforating well casings



Dec. 3', 1935. PR|KEL 2,022,976

APPARATUS FOR PERFORATI'NG WELL CASINGS Filed July 23, 1934 \nvenior: Gorffried Prikzl Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE APPARATUS FOR PERFORATING WELL CASINGS' Gottfried Prikel, Bucharest, Rumania, assignor to Shell Development Company, San Francisco, Cahf., a corporation of Delaware Application July 23, 1934, Serial No. 736,473 In Rumania July 28, 1933 2 Claims. (01. 81-188) This invention pertains to the art of perforatrels, each holding a projectile. When the explo-.

sive is fired by means of an electrical detonator, the projectiles simultaneously perforate the casing on opposite sides, the recoil being thus neutralized, and possible damage to casing as well as waste of explosive energy being prevented.

I have now found that the use of a perforator of this type in small-diameter casings gives rise to considerable difliculties, since in that case it is impossible to design an adequately large explosive chamber in combination with sufliciently long projectile barrels.

It is the purpose of this invention to solve these difficulties by providing a relatively elongated explosive containing chamber or several of such chambers, each in communication with two or.

more projectile holding barrels positioned at different levels, the axes of these elongated chambers being at a substantial angle with the axes of the barrels. Since the gases of an explosion act with equal force in all directions, the pressure exerted on the projectiles will be in this case the same as if the axes of the explosive chamber and of the barrels were coincident. j

The principle of my invention will be clearfrom the following description taken with reference to the drawing attached, which gives a vertical cross-sectional view of a preferred embodiment of my device. It is understood that neither the description nor the drawing are intended to limit my invention to this one form since, as has been stated above, the axis of the elon'g'atedexplosive chamber, or chambers, may be positioned at any angle, including a right angle, to the axes-of the barrels, and therefore coincide, or lie parallel with the axis of the perforator itself.

Referring to this drawing, the body C of the perforator contains two obliquely located explosive chambers A and A1, which lie symmetrically with regard to the vertical section as well as with regard to a horizontal cross-section taken at the middle (in some cases the chambers A and A1 may be connected to form one chamber common to four or more projectile containing barrels). These chambers are connected with symmetrically arranged projectile barrels B1, Ba, Ba and B4, holding projectiles P1, P2, P3 and P4. Pref- 6' erably, there should be at least four barrels to each perforator, although any number which is a multiple of four may be used. The projectile barrels are perpendicular to the axis of the body and are all bored in the same plane. The cham- 10 bers A and A1 are closed by means of perforated plugs K, through which a wire is passed to ignite the detonating cap H. The plugs K may be braced against each other by means of a special wedge (not shown) to prevent their being eject- 15' ed by the explosion. The wire is insulated by a rubber stopper L, held in place by a wooden plug M. The inner ends G of the barrels B1, B3, B3, and B4, are of trunconical' shape, and hold a copper plug This plug F, which may be made 20 of any other material having semi-plastic properties under high pressures, is pressed into its position by the outside pressure, whereby it seals the explosive chamber. A ringv R holds the projectile in its position. 25

All parts of the perforator are symmetrical and are shown arranged in the same plane, so that all the reactions are balanced in the interior of the body. No recoil effect causing damage to the casing or to the device is therefore possible. 30

Any number of perforators of the type described above may be combined to form achain by any connecting means such, for example, as two-part sleeves D, which grip a shoulder E formed on the body of the p rforator. A copper ring, or a ring 85 of other semi lastic material may be interposed to dampen the unavoidable jolts.

The middle part of the body may be thickened eccentrically to permit a more favourable location of the diiferent parts.

I claim-as my invention:

.1. A casing periorator comprising a body member having two elongated obliquely and symmetrically located -explosive containing chambers, said chambers converging to a common out- 45 side opening, each of said chambers being in communication at either end with a projectileholding barrel, said barrels having their outside openings facing diametrically opposite sides and their axes perpendicularato the axis of the per- 50 forator body and in the same vertical plane, and means for simultaneously exploding the charges in said chambers. I

2. A plurality of well casing peifora'tors de-" scribed in claim 1 connected together in series.

GOT'I'FRIED PRIKEL. 

